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BOOSTXL-DRV8323RS: Need a solution

Part Number: BOOSTXL-DRV8323RS
Other Parts Discussed in Thread: DRV8323, DRV8350

Hello Team TI,

Here am attaching DRV8323RS Schematic,

i have some doubts about VM and VDrain.

(If i give 12 V for VM for DRV823RS power supply and VDrain voltage is upto 52V,  and what is the status voltage of input gate drive GHx,SHx,GLx)

Pls some one explain it.

and any one have schematic for above one.

Thanks,

Suman Subburaj

  • Suman,

    Thanks for posting on the MD forum!

    The DRV8323 device requires VDRAIN and VM to be similar in voltage. If VDRAIN is much higher than VM, the charge-pump which is VM referenced will not be able to keep the high-side FET on. The VDRAIN voltage will be present at the SHx node when the high side FET turns on, if the VCP voltage is less than the SHx voltage then the Vgs of the high side FET will not be able to keep the FET on.

    Regards,

    -Adam

  • Thanks for your kind information Adams,

    if i choose Vdrain and VM as a same voltage (52V) whats happens in a SHx node and GHx,GLx nodes,

    and another one question is, internal buck regulator output current is 600mA,if its possible for increase current ratings..?

     

  • Suman,

    The GHx supply is the charge pump (VCP), this will be around 11V higher than the VM supply voltage so that the high side gate can have Vgs of ~11V when the SHx node is at the VDRAIN voltage (VCP will be 52V + 11V in your case).

    Please note that the max recommended VM is 60V in the system so 52V does not leave much headroom for BEMF, braking, etc. Usually we see the DRV835x used for 52V input as it has up to 100V recommended max.

    The GLx node is powered from VGLS, the GLx node is GND referenced at the low-side FET source so this supply is simply ~11V.

    Unfortunately we cannot increase the current capability of the internal buck. I would suggest an external buck if you need more current.

    Regards,

    -Adam 

  • Dear Adams,

    Thanks for your support,

    you are preferred DRV835x series driver ic,

    my power supply is 52-60V,(around)

    if i give pwm voltage are 3.3 v for input (Red ink marked) if it's ok for this input voltage

    and what about the pin status of GHx,SHx,GLx pin nodes  (Yellow ink highlighted) bcz am choosing mosfet VGS is +/- 20v

    and pls tell me a diff b/w SPI and H/W what is the need of it... 

  • Dear Adams,

    What about the status of of questions..?

      

  • Suman,

    Please refer to the datasheet, the input voltage range is mentioned here, up to 5.5V can be applied to the inputs:

    For the FET Vgs, is this the max limit for the Vgs? Our device is designed to apply nominal 10.5-11V to the upper and lower FET Vgs:

    The two device types are with respect to control, the SPI device uses software to control the device settings such as GAIN, IDRIVE, protection trip points, etc. The hardware device uses external resistors to set the same settings as above.

    Note that the information above is from the DRV8350 datasheet because the DRV8350 will need to be used with 60V power supply.

    Regards,

    -Adam